THE MINNOW 141 



The minnow is one of the most familiarly known 

 inhabitants of our waters, for it abounds in most parts of 

 England and Southern Scotland, although, as will be noted 

 presently, there are some singular gaps in its range. Of 

 the thousands of people who are accustomed to see these 

 little fish swarming in clear, swift streams, many would 

 be surprised to learn that they are to be numbered among 

 the carps, so widely do they differ in habit and action from 

 the heavier members of that great family, and in colour 

 from the rest of the silvery genus Leuciscus. 



In length the minnow measures five or six times its own 

 •depth, and its thickness is about two-thirds or three-fourths 

 of its depth ; consequently it has a plump, muscular 

 appearance, which, combined with Its elongated form, agrees 

 well with its incessant activity, for minnows may very seldom 

 be detected at rest. The snout is rounded and arched over 

 a small, but exceedingly serviceable, mouth. The body is 

 covered with delicate scales, so small that eighty or ninety 

 of these may be counted along the lateral line, or about 

 twice as many as in the roach. The colour varies, not 

 only with the season, but from day to day, and even from 

 hour to hour, the prospect of a good meal being quite 

 •enough to cause a marked change in the complexion of 

 this little fish. The mechanism of this colour variation 

 has been explained to consist in two layers of pigment cells, 

 one above the other in the skin. The outer layer has star- 

 shaped cells containing black pigment, which contract on 

 occasion and allow the light to be reflected from a yellow 

 pigment in the inner layer of cells. Excitement, therefore, 

 which betrays itself in the human countenance by a flush of 

 rose-colour, changes the aspect of the minnow from grey 

 to gold. In spawning time, when the males are brightest, 

 they may be described as dark olive on the back, with 

 a black band or line extending from head to tail, sometimes 

 i)roken into blotches or spots. Metallic lights gleam through 



